5.04.3: update_fwd: unknown/strange object

[Serge D. Mechveliani]

Dear GHC team,

I build by new DoCon program under  ghc-5.04.3,

installed from RPM to  i386-unknown, RedHat Linux. 

Under  -Onot,  the command     make space=-M22m docon
builds the thing successfully. 
And for less memory, say,      ...          16m ...,
it ends with

  ...
  pol/Pgcd_.hs:184:
    Warning: No explicit method nor default method for `toSquareFree'
             In the instance declaration for `GCDRing (Pol a)'

  =================== INTERFACE HAS CHANGED ====================
  No old interface available

  ghc-5.04.3: fatal error: update_fwd: unknown/strange object  38344
  make: *** [obj] Error 254
 

I expected of GHC to report of exhausted memory.    
Probably, such behavior is not fatal for may aims, 
but if you consider this as an interesting bug, I could send the 
archive. 

-----------------
Serge Mechveliani
mechvel@botik.ru